In September 1999 three people were shot dead at a hospital in Anaheim, California by Dung Trinh. Police said he was angry about his mother's death.

On 5 August the same year three people were killed in Pelham, Alabama, when a 34-year-old man opened fire at his workplace.

Shooting rampage

Eight days earlier, nine people were killed when trader Mark Barton went on a shooting rampage at two local stock trading firms in Atlanta, Georgia after first killing his wife and two children. He later turned the gun on himself.

The Santana school suspect had reportedly been teased

On 11 June 1999 three people were killed and four others wounded by a gunman who opened fire at a busy suburban Detroit office building in Southfield, Michigan.

Two months earlier, Sergei Babarrin, 70, was shot dead by police marksmen after walking into the Mormon church's Family History Museum library in Salt Lake City, Utah and opening
fire, killing two people.

In the same month, two student gunmen killed 12 other students and a teacher at Columbine High School in Littleton, Colorado before killing themselves.

Capitol shooting

In July 1998 a gunman with a history of mental illness blasted his way into the US Capitol in Washington DC, killing two police officers before being shot and captured.

The availability of guns has come under scrutiny

In March 1988, a state lottery worker shot four state lottery executives and then killed himself in Newington, Connecticut.

In December 1997 at Heath High School in West Paducah, Kentucky, a 14-year-old boy killed three students attending a prayer meeting in December 1997.

Two months earlier, at Pearl High School in Pearl, Mississippi, a 16-year-old boy fatally stabbed his mother at home, then went to school and shot to death two students, including his former girlfriend.